Safety clutch



Feb. 19 ,1924. "1,484,221

F. E. ISRAEL SAFETY CLUTCH V 4 1,484,221 F. E. ISRAEL SAFETY CLUTCH lleb. 19 1924.

. "Filed Feb. I11, 1922v s sheets-sheet 2 F'lngd E- 151" aal reame' rea. 19, 192e.

. erica.

FLOYD EDSQNSRAEL', OF LE ROY, KANSAS.

. SAFETY CLUTCH.

Application filed February'll, 1922. Serial No. 535,847.

To all w/om t may concern:

Be it known that I, FLOYD- E. ISRAEL, a

citizen ,of the United States, residing at; Le Roy, in the countg7 of Coffeyl and State This" invention relates to improvements.

in safety clutches. -l z The `primary object of the' invention lis the pi-ovision of a' safety clutch adapted for automatic disconnectionl between drive and driven shafts, incident 'to overloading of the` former by reason of) addedwork, frictionvof parts, or excessive drag.;

A further 'object of theinvention is the provision of an automatic4 releasing clutch to prevent overload of a I,driving shaft, adapted for quick adjustment to; Iplace the sainel in4 operative relation to` establish a drivingl 'connection between driving and ydrivensha'lfts. i y

A further'-objectof the invention is the provision' ofj'an improved'fsafety clutch of the above described character, which is simple in construction, automatic in operation, and adapted for 'operation upon forwardv and reverse speeds, and one which is particularly well adapted for use in'connection with pow-- er mechanisms employing a clutch, to prevvent strain or breakage of any of the parts connected thereto.

Other objects and advantageswill be apf parent during the course of the following :z5 detailed description.

ln'the accompanying drawings-forming a lpart of this specification, and wherein sim'- ilar reference characters designate corresponding parts throughout the several ai) views,

' :Figure 1 is a longitudinal cross sectional view taken through the improved safety clutch and showing thesame in operative relation to driving and driven shafts.

Figure 2 is a longitudinal cross sectional view taken through the improved safety clutch mechanism and showing the manner in which the same operates to disconnect the driving and driven shafts.

Figure 3 is a cross sectional view .taken i v.smbstantially on the lined-'3 of Figure 1.

F ign re 4 is a transverse cross sectional View takensubstantially on the line 4 -4 of Fig- `urev 1. i

Figure 5 is a plan view of the safety clutch details showingv the same in relative position during a driving connection between the drive and driven shafts.

` Figure 6 is a plan view of the improved clutch details showing the same in relative positions after a disconnection of the drive and driven shafts by automatic operation of the clutch mechanisn'l.

Figure 7 is a perspective view of a clutch member part embodied in the improved safety clutch mechanismi Figure 8 is a fragmentary elevation showing the manner in which several details of the improved safety `clutch cooperate'to provvide a driving connection of the power and driven shafts.

In 'the drawings, wherein for the purpose of illustratlon 1s shown the preferred emsv bodiment of my invention, the letter A designates a driving shaft, and B a tdriven shaft; the shafts A and B being connected by the improved safety clutch mechanism C.

The details of the improved safety clutch mechanism C preferably' include a housing 10 formed of parts 11 and 12, which may be lsuitably connected by bolts 13, in order that access may be had to the safety clutch details. The safety clutch mechanism is of course, susceptible of adaptation to power propelled vehicles, as well as for use upon any type of power machineryv embodying a clutch, such as lathes, drilling machinery, metal cutting mechanisms and the like.v It is preferred that the drive and driven shafts -A and B respectively, bein alignment and have their ends spaced from each other and provided with a .relatively small diametershaft-15, the ends of which 'are journalled in the ends of the drive and ldriven shafts. Bearing sleeves, or antifriction bearings may he provided, if desired, to support the ends of the shaft 15 in the ends of the drive and driven shafts A and B. An external clutch lcone 17 may be splined, upon the end 18 of the shaft B so that the cone ortion 19 thereof extends outwardly towar( the shaft 15 and driven-'shaft A. preferably embodies vthe ordinary annularly grooved collar 20 adapted for use in connection with a regulating mechanism 22, which embodies a lever 23 upon an end of which is formed an ordinary yoke (not shown) to cooperate in the groove 24 ofthe collar or sleeve 20; Sahilever 23beingv pivoted, as at 25, toa quadrant 26, secured as by retaining elements 27, to the exterior4 ot the casing portion 12. The quadrantlQ is preferably pro- T he clutch part 17, i

vided with three toothed Adepressions 27a, 28 and 29 adapted for engagement by the paWl 30 pivotally mounted upon thelever 23, and operated by the usual mechanism 31 from the handle portion of the lever 23; and by which means the lever 23 may be held in a determined position for disposal of the clutch part 17 in a definedv location longitudinally of the shaft B; yet permitting rota.- tion of said clutch part with the shaft B by reason ot the key 33 fixed to the shaft B.

A spring 34 is provided, preferably of the section 38, may, of course, slide longitudiv nally upon the shaft 15, but is keyed against rotation about its supporting shaft 15 by the key member 39 fixed in the shaft 15. relative longitudinal movement permitted by the clutch sections 17 and 38 is limited by pins 40, lwhich project radially inwardly from the outer marginal edges of the cone 19, and are adapted for contact with the annular shoulder 42 provided circumferentially about the section 38. For cooperating with the releasing mechanism 45, to be Asubsequentl described, the Vclutch section 38 is provi ed with an annular flange 46 extending outwardly from the shoulder 42, and which is rovided with a pair of proximately posltioned depressions 48 and 49, disposed invvardy from the outer marginal edge 50 of the ange 46 to provide a shoulder projection 51. Similarly, diametrically opposed to the depressions 48 and 49, a second pair of depressions 53 and 54 are provided, to provide a. shoulder 55 altogether similar to the shoulder 51.

Referring to the mechanism 45, the same preferably includes a disc 56 keyed as at 57, upon the extreme end of the drive shaft A and, or" course, within the casing 10; a second disc 58 being keyed as at 59 to the intermediate shaft 15, substantially midway of the facing ends of the drive and driven shafts A and B. Both discs 56 and 58 are securely fastened to the shafts A and 15 respectively, against longitudinal or rotational movement with respect to the shafts upon which mounted. The member 58 is provided at diametrically opposed points lWith slots 60, which have the arms, pavvls, or levers 62 ivoted therein as by screws 63, which are tastened radially, inwardly from' the outer marginal edge orp the disc 58, so that they intersect the slots 60,155 properly provide for The O62 incassi pivoting of the arms 62. The ends of thearms 62 extending toward the clutch sectionv 38, may he tapered, and inturned toward the axis of the shaft 15; having suitable bearing rollers 64 rotatably mounted upon these inturned ends. The op ositeends 65 of the..

arms 62 extend towar the disc 56, rojecting through arcuate slots 68 formedj transversely therein. The slots 68 are relatively longer than the width of the arm ends 65 which they receive, and are referably struck from the axis of the sha t A as a center.

In effecting the purpose for which the improved safety clutch has been provided,

' it is desired that the clutch section 38 be normally urged toward its adjacent disc member 58, as by the tensionsprings 69,- which engage suitable eye bolts 70 and 71, disposed Within the clutch section 38 and in a side or' the disc member 58 respectively. The clutch arms 62 bear a definite relation to the bearing shoulders 51 and 55 provided upon the clutch section 38'; the section 38 and disc 58 being so relatively keyed tothe bear directly upon the outer marginal edge of the shoulders 51 and 55, when said arms 62 are disposed in longitudinal alignment with respect t6 the alignment defined by the drive and driven shafts A and B. Thus, when thearins 62 are in such osition, the vsprings 69 will maintain the c utch section 38 in tight engagement against the rollers 64 of said arms, and as can readily be'seen from Figure 1 of the drawings.

Each of the arms or levers 62 are maintained in proper alignment to hold the clutch section 38 in the position described above by springs and. 76 disposed unon each side thereof; the same being refera ly tension springs so that theends o the arms 62 are counter-balanced, so to speak, so as to maintain the alignment above described.

The springs 75 and 76 are supported by the Lshaped bolts 77 upon the sides of the armsv62, being inserted at their other ends through extension sleeves or projections 78.

sha-ft 15, as to have the rollers 64 of the armsv The extreme ends of the springs 75 and76 which extend thru the sleeves 7 8 are 'preferably screw threaded, for receiving the nuts v 7 9, whereby the tension of said springs A7 5.

and 76 may be varied, in order to accommodate various loads upon the drive shaft Y A, In other words, in order to rock'either of the arms 62 upon their pivot pins 63,

the force upon the ends 65 of said arms nec essary to perform such Work, may be varied by adjustment of the springs 75 and 76, which maintain said arms 62 1n their roper positions with respect to the 1shonl ers 5i. and 55 of the clutch section 38.

Assuming the clutch sections 17 and 38 to be in engagement, as illustrated in Figure i, the section 17, of course, being held in en of the drive and gagement with the section 88 by reason of positioning of the lever 23 to have its pawl 30 engage in the depression 27a. The driving shaft A slowly starting under the nccessary power to rotate the shaft B, will rotate independent of the shaft B and the disc 58, upon which the arn'is 62 are disposed,

, until end edges 80 of the slots GS in the disc member 56 engage the lateral edges ofthe diametrically opposed arms 62. lf the d1- reetion of rotation of the drive shaft A .is 4to the lright as indicated by the arrows 1n Figures 1, 3, and 8, the strain of receiving vthe power from shaft A will be placed upon the tension springs 75. The power from the shaft A Willvset the. shaft 15 rotating by reason of connection of the disc 58 and its pivoted arms 62 therewith. Because of the frictional engagement of the clutch sections 17 and 38, the driven shaft B will be rotated by the drive shaft A. V

Should the drive shaft A start its rotation at a high speed ratio or should the shaft B have a load thereon greater than the safety clutch mechanism C is adjusted to withstand, the drag incident to such conditions Willcanse the arms 62 tol swing upon their pivots; the power shaft A having, of course, been placed in operation. As illustrated in Figure 6, when the arms 62 are rocked upon their pivots, theA rollers 6% thereof, lwill ride off the shoulders 51 and 55 against which they rest. The springs 69 asserting themselves WillI force or pull the clutch section 38 toward the disc member 58 and whereby the roller ends 64 of the levers or arms 62 are disposed in the depressions 49 and 53 of the clutch section 38. eration of the clutch section 38 sliding upon theshaft -15 will release relative engagement of the clutch sections 17 and 38, and of course, throw driven shafts.

In order to bring the 'clutch section 38 back into engagement with its companion section 17, it is necessary lating lever 23 until the substantially in the depression 29 provided in the quadrant 26. During this movement, the inwardly projecting pins 40 of the clutch section 17 will engage the shoulder 42 of the clutch section 258, and whereby said clutch section 38 will be, slid upon its shaft 15, so that the roller ends 64 of the arms 62 are released from the depressions in which they were automatically positioned. .The power upon the drive shaft A having been reduced, the springs 7 5 and 76 will counterbalance, so that 'the arms 62 are again positioned in alignment with the power driven shaft. v In this relation the clutch section 38 is again held by means of the roller ends 64 of the arms 62 resting against the shoulders 5l and 55. y

The safety clutch C will Work automatithe clutch section This opont the driving connection to swing the regu-y pawl 30 thereof is` cally during rotation of the power shaft A in either direction. As indicated in Figure (5, rotation of the power shaft. A is to the left, and as there was an overload upon the driven shaft l, the tension ofthe supporting'springs To were overcome, so that the arm 62oper-- ated in reverse manner to that abovel described. whereby the roller ends thereof were positioned in the depressions 18 and 54 of 38: the result of course, being the same, namely` disconnection of the power and driven shafts.

So long as the load upon` the driven shaft Y B remains greater than that for which the safety clutch mechanism C is adjusted, the power shaft A' will-rock the arms ($2 to release relative engagement of the clutch cone sections 17 and $38 to automatically disconnect driving connection. This disconnection will continue, no matter how often the operator swings the lever 23 to right the position of the clutch section 38, so long as the overload upon the driven shaft remains.

The springs and 76 may be adjusted4 as to their tension and in which manner various loads upon the driven shaft B may be accfnnmodated. i

It' the driver `ot' the mechanism desires to release the driven shaft B from connection with the power shaft A, the same can readily be done by swinging the lever 23 until the pawl 30 thereoftis disposed in the depression 28, which merely has the etfeet of movingthe clutch section 17 upon its shaft l out of relative engagement with the clutch section 38; this operation heilig effected without rocking of the lever 62 to perform the releasing operation above described.

From the foregoing description of the improved safety clutch, it can ,readily be seenY that various loads may beplaced upon the driven shaft B without liability of twisting or strain upon any of the shaft parts. Should an operator of a cutting machine, have a dull cutting tool upon the driven shaft B, the overload which a cutting operation would impose upon a driven shaft B would automatically throw the power and driven shafts A and B respectively out. of driving connection.l Various changes in the shape, size and arrangement of parts may be made. to the illus trated construction of the improved safety clutch, without departing vfrom the spirit of the invention or the scope of the claims.

I claim: l

1. In a safety clutch, the combination with a pair of shafts defining drive and driven shafts` a thi'rd shaft bearing in said drive and driven shafts, a pawl, means pivotally and resiliently supporting said .pawl on the third shaft., a clutclrpart on oneof said pair vof shafts, a second clutch part mountedon ill ment withsaid pawl, and' means on the seeond of said pair of shafts for engaging said pawl whereby upon overload on the driven shaft. the pawl will be swung to release the second clutch part from engagement with the first clutch part to release a driving connection between the drive and driven shafts.

2. A. safety clutch mechanism comprising a pair of shafts defining drive and driven shafts, a third shaft hearing in said drive and driven shafts, a clutch embodying a part splined on one ofthe pair of shafts and a second part splined on the third shaft, holding means supported from said third shaft. and adapted for maintaining saidsecond clutch part in engagement with the first mentioned clutch part to establish a driving,r connection between the shafts upon which tlfe clutch parts are mounted, and means on the second of the pair of shafts adapted for env 2(raging said clutch holding means to move the first shaft with the other shafts and upon overload upon the driven shaft adapted for movenient whereby theseeond clutch part will automaticallvbe released to disconnect the elntoh.

3. A safety clutch mechanism comprising in combination a pair of shafts defining drive and driven shafts, a third shaft supported from the ends of the said shafts, a pair of cooperating,l clutch parts splin'ed on the third shaft and one of the first mentioned pair of shafts. resiliently supported means on the third shaft for holding said clutch parts in engagement with each other to establish a drivingA connection between the drive and driven shafts, said resiliently supported means adapted for movement upon overload on any of the shafts to release the clutch parts to disconnect the. drivingv engagement between the drive andY driven shafts.

4. A clutch mechanism embodying a drive shaft, a driven shaft, a third shaft bearing in the ends of said drive and driven shafts, a clutch part on the driven shaft. a clutch part on the third shaft adapted for establishing driving connection between the third and driven shafts, adisc membeV keyed to 'the third shaft, an arm pivotally connected to the disc member, i means adapted for maintaining said arm in position to hold the clutch parts in relative engagement, spring means engaging said-disc and clutch part on the third shaft to normally pull the latter clutch part toward said dise, and means on the drive shaft engaging said pivotally n'ionnted arm at an end opposite `to its clutch engagingend. whereby when the load on the driven shaft is more than the resilient holdingmeans, the clutch part on the third shaft will be antomatiwilly released from its eooperatingr clutch part.

5. A clutch meehanisni comprising drive and driven shafts, a third shaft bearing' between the drive and driven shafts, a clutch part longitudinally movable on said. driven shaft, means for moving said clutch part and holding the same in a detern'iined position, a second clutch part keyed to sahfthird shaft and longitiulinaltv slidable thereon adjacent said first mentioned clutch part, said second clutch part having a recess therein, a member tixedly keyed on said third shaft adjacent said second clutch part, an arm pivotally supported b v said member` spring means engraging'said arm and actingl in opposite directions to maintain said arm in a resiliently supported predetermined position upon said member so that. the' same will engage said set-ond clutch part to normally maintain the same farthest extended towardy the lirst mentioned clutch part, spring means connectingI said. second clutch part and the member on said third shaft normally tending to move the said second clutch part toward said member, and means carried by said drive shaft engaging said pivotally mounted arm at an end opposite to the end of said arm which engages said second mentioned clutch part, said armadapted to swing against the springs which support the same incident to an overload upon the driven shaft so that said arm will ride into the recess of said second mentioned clutch part lo release relative engagement with the first mentioned clutch partA rigori) Ensor tenant. 

